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Breadboard Arduino 3.3v

Introduction: Breadboard Arduino 3.3v

I wanted to use bare Atmega 328p chip at 3.3 volts with an internal clock at 8MHz for small and compact projects. After some research on the net, I was able to retrieve all the informations to make it work.

Here are the steps to follow.

-First, hack the IDE with a new Bootloader option.

-Second, upload an ISP sketch in the programming Arduino.

-Third, wire everything together.

-Finally, load the new bootloader and sketch in the bare chip.

What you need:

-Arduino Uno or any other type of board will do (pro mini, Due, ect...)

-Atmega 328p chip ( available on ebay)

-Breadboard

-Dupont wire.

That's it !

Step 1: Hack Your IDE With a New Bootloader.

What's a bootloader??

It's a small program included in all micro-controller (Arduino chip) to set it's basic working parameter. Example: communication speed, accessible memory, minimum working voltage.

This code will allow us to use the Atmega 328p chip at 3.3volt without external clock to set it's speed.

First we need to find the file board.txt in the Arduino folder. (the one in program file/Arduino/hardware/ for windows or usr/share/arduino/hardware for Ubuntu). Depending on the software version, this file can be in different folder. Once you find it, do a backup of this folder in case thing goes wrong.

Step 2: Bootloader File

Next, open the file to see all the Arduino boards with weird settings. Just go to the last line of the file and copy/paste this script:

Step 6: Uploading Your Sketch in the Atmega328p Chip.

To use the board as a programmer, you need to press SHIFT on the keyboard as you click on Upload to send the sketch to the chip. Otherwise it will not work ( you'll see Upload Using Programmer near the Save button)

This setup is useful to use with display like the Nokia 3310/5110 or a TFT display who work on 3.3 volt.

Hope this post will be useful to some of you. By the way I'm French Canadian so excuse me if I made some mistake!!!